algae

Question 1

define the term algae

Answer 1

Aquatic organisms that are photosynthestic, oxygenic autotrophs that are typiclally smaller and less sstructurally complex than land plants
- A loose grouping of organisms
- Over 50% of glabal primary production
- Highly productive in shallow coastal waters but most productivity in open ocean

Question 2

Rhodophyta (red algae) habitat and characteristic

Answer 2

Rhodophyta (red algae)
habitat- benthic
characterisitc: main pigments
Main pigments Chlorophyll a
Phycoerythrin
Phycocyanin
- plastids Single thylakoid lamellae with phycobilin granuales on the surface( reflects early endosymbiotic cell as its simple)

• Storage products : Floridean starch
• Cell covering: Cellulose with sulphated polysaccharides such as sugar and carrageenan(can use for gelling agents eg agar gel,lipstick)
• flagella None
• No. of species: About 5-6000, 95% marine
• morphology: Mainly multicellular bases on filamentous architecture

Representative marine genera: Ceramium, polysiphnia,jania,corallina,Eucheuma,hypnea, porphyra

Question 3

charcterits of the major groups of each algae

Question 4

decribe the role of algae

Answer 4

Economic importance
- Gelling agents (from cell wall composition
- found in cosmetics, ice cream, toothpaste, ect
- Food: nori, laver bread
- Seaweed farming doen in developing countries in shallow coastal waters

Question 5

describe Chlorophytes main characteristics and habitat

Answer 5

Main pigaments Chlorophyll a and b
b-carotene, lutein zeaxathin
- plastids Thylakoids in groups of 2-6
- Storage products Starch in chloroplast
- flagella Usually 2 sometimes 4 to many
- Cell covering Organic scales
- No. of species 180, marine and freshwater
- Morphology unicellular
- habitat planktonic
- Representative marine genra Tetraselmis, Bathycoccus, Pterosperma, Halosphaera

Question 6

main role of chlorophyte

Answer 6

mainly used fro aqua culture
halimeda a type of green alga creates sediment ( calcified plates break down when plant dies and produced in calcareous sand )

17 species of green alga are invloved in ass spawning of algae

Question 7

describe phaeophycea (brown algae main characteristics and habitat

Answer 7

• Chlorophll a,c and fucoxanthin
• Multicellular,benthic,marine
• Includes the largest marine plants
• Variety of life histories

Reproductive strategies
- Isomorphic alternation of generations
– Morphologically similar
- * Heteromorphic alternation of generations
– Morphologically dissimilar
- * Heteromorphic generations with greatly reduced gametophyte (or single phase?)
– Reduced sexual phase

Question 8

role of phaeophyceae

Answer 8

harvestes for alginate (gel agents)